Question

(x^2+2xy+y^2)-4(x^2-y^2)+4(x-y)^2

如题，请速度解决....明天教 分解因式

Answer 1

(x^2+2xy+y^2)-4(x^2-y^2)+4(x-y)^2
=(x+y)^2-2(x+y)(2x-2y)+(2x-2y)^2
=(x+y-2x+2y)^2
=(3y-x)^2